Body Line Problems in handstand drill and in MN/PE(1 to 3)

My shoulders' angle is closing and the knees are getting detached from the floor as soon as I do PPT and squeeze my abs.

What can I do to fix this? It's a very basic drill ,for handstands + manna's first 3 PEs, which I'm not able to do for a certain reason 

Could this be happening due to very tight and weak Iliopsoas&Rectus femoris(quadriceps)?

Thanks

take you belly in and up. this will activate the external oblique , this muscles perform actively a little posterior pelvic tilt.

Stretch.

On top of Alex's recommendation, this issue is also excerbated by tight hip flexors.

Yours in Fitness,

Coach Sommer

Coach Sommer said:

Stretch.

 

On top of Alex's recommendation, this issue is also excerbated by tight hip flexors.

 

Yours in Fitness,

Coach Sommer

I'm very glad my guess was proved true. I always neglected my front splits because I didn't have any reason to train them..

Alessandro Mainente said:

take you belly in and up. this will activate the external oblique , this muscles perform actively a little posterior pelvic tilt.

Thanks a lot brother, great advice! I could activate it , but just for a short time. It'll take some time(& patience) to fix the main factor.

Btw, I'm confused which is good... Why is it necessary to activate external oblique when I already had PPT?  Any cues to how you noticed I lack it?